Illumination for a key hole dates back in the prior art before the turn of the century. Generally the illumination is direct--the key hole per se is illuminated or surrounded by an illuminating means; or indirect where there is an auxiliary light with a reflector to direct the light upon the key hole area.
In the indirect illumination of a key hole there is found in the prior art many such means wherein the light is not continuously illuminated. In these, the illumination is actuated by a switch.
Again, many of these indirect systems are self-powered. Success has not, for one reason or another, come to these prior art systems. Mostly they are crude and either are lighted at all times from house current or dependent upon batteries and the actuating switches are of the mechanically activated on/off type. Further, although a switch may be easier to locate than a key hole, the normal switch is not the answer for ready accessability.
Typical of the prior art are U.S. Pat. Nos. 2,529,234, 2,661,417, 2,011,692, 3,590,234, 3,270,191, 3,711,694, all now reclassified in Class 362/100 of the United States Patent Office Classification System.